Hearing devices which do not require individual otoplastics have been available on the market for some time. Plastic plugs take the place of the otoplastics in this case. The acoustic characteristics of such plugs nevertheless restrict the universal applicability of these types of hearing device. To provide for more severe hearing loss, in many cases acousticians glue a conventional otoplastic or an ITE shell (in-the-ear) to the sound tube instead of the plug.
The tubes used in hearing devices are however exposed to the prevailing environmental conditions and are thus subject to an increased ageing process. Consequently, the problem consists in the tubes having to be exchanged again after some time. This is however not easily possible due to the minimal diameter and the material used for the tube. The otoplastics and ITE shells can only be reused, if at all, by counterboring the tube element glued thereto. Reuse involves cutting the new piece of tube to the corresponding length and re-gluing it into the bore of the otoplastic and/or ITE shell.
The publication DE 20 2005 004 245 U1 discloses an in-the-ear hearing device shell. A sound tube is fastened to a flange by pulling the tube over said flange. A groove in the flange is used to fix the tube.
Furthermore, the patent application DE 195 23 991 B4 describes a hearing device having a suspended earpiece and a sound tube. The suspended earpiece also features a rotating groove at the end at which the sound tube is disposed.
Finally, the publication DE 94 06 801 U1 discloses a sound tube, which is held in place by means of an integrally molded annular collar on the front shoulder of a tubular support.